Problem: Solve for $q$ : $-13 + q = -14$
Add $13$ to both sides: $ \begin{eqnarray} \\ -13 + q &=& -14 \\ \\ {+13} && {+13} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{-13 + q} &\hphantom{=}& \hphantom{-14} \\ q &=& -14 {+ 13} \\ \end{eqnarray} $ Simplify. $ q = -1$